Find great deals on eBay for 4.3l vortec heads. ... LH Lift Lug Cylinder Head and Block Mounted 4.3L V6 Vortec Engine Chevy Blazer. I saw this while researching Vortec heads and decided I would share with the group. Hello all,subject are heads,vortec heads, ... those first SBC heads you buy. Using 243 casting heads, a smaller camshaft and an additional 18 cubic inches. ... the Vortec heads require modifications to the valveguide to allow more lift Upgrading Valve Springs on Vortec Heads All Coiled Up / 5. Hi Everyone, Im looking to modify a set of Vortec heads for oval track racing application. The following cost and time figures have been submitted by builders. As many know, ... Easy upgrade Vortec Head for more lift. A few more ... add additional expense to safely accommodate for more than .425 lift. Warranty see all Warranty. From Crankshaft ... Pre-Vortec heads. Dart is about to release their new iron 8.1 GEN 7 BBC heads. The stock retainers and springs do not allow for more then around .460" lift. ... reduce maximum lift capacity. Im trying to make them suitable for my selected camshaft. The stock springs will only accommodate around 0.420 inch of valve lift. ... lift capacity. from Shelby has a nice '69 two door! Vortec heads are pretty good heads don't get me wrong. A Guide to Vortec vs OE Small Block Chevy Heads ... By the time a racer was done modifying the heads, ... on anything over .460 lift. ... so they need to be milled if used on a 305. 2018 FACTORY STOCK RULES. ... More. If a year of build was provided, we have included that information, otherwise the date of Chevy 305 engine. 1969; Engine: 350; Transmission: TH350 . The stock retainers and springs do not allow for more then around .460" lift. The Dart iron 8.1 heads are $654 a piece bare, 26 pairs are being machined, 16 More info on them can be seen at Vortec L31 cylinder head. I'm a big believer in more lift .500+ anything else is a waste of free HP. The LS2 was introduced as Corvettes new base engine in 2005. Here's an article on modifying the heads and another. BODY: Any American made stock passenger car body on a stock unaltered full frame, or Chrysler & Ford unibodies. The classic iron Vortec head offers quite a few benefits as a budget performance head, but it needs some help if you add a cam with more than 0.450-inch lift. Brian Crall . A little info back to the group, I came across the following valve springs and retainers from Crane Cams that increase lift clearance on Vortec heads Ultimate Chevy Big-Inch Small-Block Cylinder Heads Cheat Sheet - Step by Step How-To Instructions, Images, Examples, and Checklists